BY edge, I meant the top and bottom part of caudal where the vertical meets the curved. A HM is preferred to have a "D" shape caudal. So the top and bottom edges should have equally long rays, making it look pointy like a perfect "D". IME fin form is inherited more from the female. If you use pointy edged females, you will have same traits in fry, not 100% though - easier to improve. Since getting (buying) perfect females is harder than males, thus IMO it's best to concentrate on working to get perfect females.

BY edge, I meant the top and bottom part of caudal where the vertical meets the curved. A HM is preferred to have a "D" shape caudal. So the top and bottom edges should have equally long rays, making it look pointy like a perfect "D". IME fin form is inherited more from the female. If you use pointy edged females, you will have same traits in fry, not 100% though - easier to improve. Since getting (buying) perfect females is harder than males, thus IMO it's best to concentrate on working to get perfect females.

The problem with looking at siblings with long anal fins, is that when you ask for a shorter one, you can only get one that is so short. If a majority of the females have long anal fins, then that is an over-all fry thing, not just the female. You can go with her and slowly work your way down. Or you can simply look at another seller. She really isn't bad. You'll never find the perfect fish. There's no such thing. You'll wear yourself out, but you can pick the best from your options. You can always work to creating your ideal fish, but you'll never find "perfect".

This female is much better than her sisters, though her dorsal could be better. Like HK said, you can't find a perfect female thus have to work for it. If her siblings mostly had long anals, she might produce more with long anals too. So, you just have to select the ones with the smallest anal